Rock-drill



" UNITED STATES PATENT UFFICE.

LEANDER S. \VOODBURY, OF CALUMET, MICHIGAN.

ROCK-DRILL.

SPECIFICATION forming part of Letters Patent No. 321,670, dated July 7, 1885,

Application filed February 2, 1885. (No model.)

To all whom, it may concern:

Beitknown that I, LEANDER S.Woo 01mm, a citizen of the United States, residing at Calumet, in the county of Houghton and State of Michigan, have invented new and useful Improvements in Rock-Drills, set forth in the annexed specification.

My invention relates to the mechanism in a rock-drill whose office it is to rotate the drill as it is entering the rock, its object being,

first, to avoid the unequal lateral strain that comes upon the rotating bar as heretofore used and the derangement incident thereto; second, to decrease the number of parts most affected by wear; third, to prevent the air,

which, being retained in the cylinder, acts as a cushion to prevent the piston from striking the cylinder-head, from escaping into the easing containing a part of the rotating mechan;

-ismr lt hesefibjects' are accomplished in the device illustrated in the accompanying drawings, in which- Figure 1 is a longitudinal central section of the upper end of a rock-drill cylinder, cylinder-head, piston-head, &c., as on line :0 m,

Fig. 12,the rotating-bar being shown in elevation. Fig. 2 is a plan of the ring K, Fig. 1, looking from above,with a cross-section of the rotating bar 0 where it passes through the ring.

Fig. 3 is a plan of the rotating disk ll, Fig.

1, looking from below, with a cross-section of the rotating bar 0 where it passes through the disk. Fig. 4 is an end elevation of the rotatingbar C, Fig. 1, looking from X. Fig. 5 is an end elevation of the rotating bar 0, Fig. 1,

tions of the section of the rotating bar 0 where it passes through the disk H. Fig. 9 isaplan of the washer W, Fig. 1. Figs. 10 and 11' illustrate a modification of the ring K, the former being a section on line as a; of Fig. 11,

5 which is a plan corresponding to that of Fig.

- 2. Fig. 12 is a plan of the cylinder-head in-' casing the ratchet and pawls of the rotating device heretofore used, looking from the bottom, with'a cross-section of the rotating bar where it passes through the head. This figure is for descriptive purposes, to more clearly illustratc the first object of my invention,as' heretofore specified.

Si milarletters refer to similar parts throughout thc'views illustrating my invention, and as far as possible in Fig. 12.

A is a portion of the upper end of a rockdrill cylinder. '13 is the upper end of the piston, 1 being the packing in the same.

0 is a composition-nut firmly screwed into the end of the piston, made internally to conform to the shape and pitch of the spiral wings of the rotating bar 0.

L is a metallic disk for the purpose of holding the packing-ring R, which is of some fibrous material-as leather or compressed or vulcanized fiber.

- D is the cylinder-head, 'into which is firmly screwed the disk K against the shoulder I, Fig. 1, and upon the upper face of which are cut the ratchet-teeth, as shown more clearly v in Figs. 2 and 6.

The modification of the ring K shown in Figs. 10 and 11 simply dispenses with the thread out upon its periphery, as shown in Fig. 1; and to perform the same function the cars z z are extended,as on the dotted lines 2 z, 4 Fig. 1, and through which the bolts M pass, preventing the ring from turning.

C is an elevation of the rotating bar, which is in one piece, that portion below the collar'l being of the usual form.

'1 is a solid collar upon the rotating bar, a cross-section of which, as shown, is hexagonal. It may, however, have any polygonal shape, or such modifications inshapc as indicated by Figs. 7 and S.

V is also a solid collar on the end of therotating bar to give a bearing in the head D. It also serves as an abntinent for the spring S, which may'either be wound in its place or twisted into place through the holeV', Fig. 5.

II is a disk fitted upon the collar '1 of the rotating bar, so that it will rotate with the and 6. Into the back of this disk is fitted the collar or washer W, which is cut in halves, and havingbeen driven into the disk the edges of the disk around it are staked down upon it,

This disk also has teeth out so that it is practicallysolid with the disk,and

its office is to receive the thrust of the spring S. Through the disk H isdrillcdasmallhole,

U, which is simply an air-connection between the spaces above and below the disk.

M M arebolts,\\-'hich, extendingthrou'gh the lower head, bolt the whole drill together.

F is a cross-bar, between which and the head I) is a rubber buffer, N, which receives the shock when from any cause the piston-head s'rikcs the cylinder-head.

In Fig.-12,D is the cylinder-head. G is a section of the rotating bar where it passes through the head, and corresponds to the same section in Fig. 2. If is the collar, having ratchet-teeth upon its periphery, into which engage the pawls J, which pivot upon the pins g, being kept engaged by springs. (Not shown.)

Having thus described the parts, I will proeecd to describe their operation and use. In all rock-drills in which the motion of the drill is reciprocating, it is necessary that it should i also have a rotary motion for the purpose of making a round hole and keeping itself clear in the hole. This rotary motion is given by the spiral bar (1, which is common to most rock-drills. The downward motion of the piston gives a rotary backward motion to the bar 0 in both devices, as indicated by the arrows, Figs. 3, 6, and 12, the shape of the teeth lifting the pawls in Fig. 10 and sliding back thcdisk 11 upon the collar T in Fig. 1. The re-engagement of the pawls in the ratchetwheel, Fig. 10, and of the teeth of the disk II, with those of the disk K, Fig. 1, prevents any motion the other way, so that when the piston is coming up it is given the rotary motion,and, as regards the rotary motion of the drill, the same results obtain in both cases so long as the devices properly perform their function.

Referring now to Fig. 12,1 proceed to show the derangements alluded to, and to avoid which is the main objectof my invention. It will be plainly seen that the resistance to the rotary motion of the rotating bar when the piston is coming up is all on one side of the ratchet-wheel H. As the piston moves over the bar with great rapidity and the inclinationof the spiral is comparatively small, the force brought against the pawlsis very great, and was the occasion of the use of two pawls in order that the strain might be divided.

by the dotted arrow, and comes against the head D with even greater force than upon the pawls, and the hole through the head becomes 'first, if no especial means are used to prevent the escape of pressure around the bar into the head, when the bar becomes loose, as

, above described, then the air that is retained in the cylinder, as in space nmg. 1, 'for the Now, as regards the bar O,the resultant of this force is in the direction indicated.

purpose of a cushion, has a chance to expand into the spaces around the ratchet-wheel and pawls, and often does so to such an extent as to render the cushion insufficient to prevent the piston from striking the cylinder-head, and damage to the drill is often the result; second, in order that the pawls J shall each receive its share of the strain, it is not only necessary that the teeth be accurately spaced and the pawls so adjusted that both will take the strain at the same time, but having been so adjusted it is also necessary that the relative position of the center of the bar 0 with the center of the pins 9 be sustained, but the wear of the head and bar, as above described, destroys this relation, and as a consequence the strain comes greater upon one pawl than upon the other, and oftentimes it comes entirely upon one pawl, which, being unable to bear it, the points of the pawls become broken or battered to such an extent that rcpai rs become necessary, and the same is also true of the teeth of the ratchet. One other difficulty follows. In order that the nut 0, Fig. 1, may work with the greatest freedom, the

bar C should be perfectly central through its length; but when any lateral motion is possible, such as has been described, the bar is thrown out of a true central line, especially as the piston is coming up and when the greatest strain is upon it, so that it is more or less cramped in the nut, and undue friction is the result.

Having thus far described the derangements peculiar to the old device, partially illustrated in Fig. 12, and which are not more theoretical deductions, but the actual results of experience, I will proceed to more fully explain my invention, by which these derangemcnts are fully and practically overcome, referring to the figures illustrating my invention. The action of the piston upon the bar, being the same as with the old device, when the piston is going down, the bar C,with the disk II, has a backward motion, the disk I-[ sliding upon the collar T as it revolves from one tooth to another of the disk K, the spring S keeping the disk ll engaged with the disk K, and always locking it when it has a tendency to move forward. The teeth of both disks are accurately cut, so that whatever be the portion of the rotation in which they are locked every tooth of thcdisk II bears equally against its mate in the disk K, so that when the piston is coming up the resistance to its tendency to rotate the bar 0 forward is equal all around the disk H, and no'lateral strain whatever comes upon the bar G. The wear upon the ring K,through which the bar passes, andiupon the bar itself at this point is reduced to the minimum, as is also the friction of the bar within the nut 0, while the strain upon theteeth of the disks H and K is so widely distributed and brought to bear upon suchan increase of surface presented by so many teeth the wear at this point also is reduced to the minimum. Aside from the re- IIO '- 1o vent any escape of pressure from the space E into the head D, I make use of the packingring R, held firmly in place by the ring L. This ring R is formed in one piece, of some fibrous material-as leather, or compressed or vulcanized fiber-which is of ayielding nature. It will be seen that any pressure within the space E will keep the packing-ring R 'close to the bar 0, effectually shutting off all escape in that direction, so that if the pistonpacking Pis also tight the desired cushion within the space E is obtained. 4 The ring R is cheaply made,and readily re- 1 placed when worn out by the one using the drill.

The spirally-forined portion of the rotatingbar 0 is common.

No claim is made uponthe cl utch H K, sim-' ply as such. p

The combination-of the various parts .de

' 3o scribed, their operation, and purpose are new.

I therefore elaim--. 1. The combination, in a rock-drill, of the bar.

rotating bar 0, the clutch H K, the washer \V, spring S, and cylinder-head 1), when one part of the clutch is fixed and forms a guide for the bar and the other part is so attached to the bar as to rotate with it, and at the same time slide upon it, when the purpose of the combination is to rotate the piston of. a rockdrill, and the parts operating to that end, except the spiral portion of the bar, are within the cylinder-head.

2. Thecoinbinati0n,with the rotatingbar,ofa rock-d rill,madesubstantially asand forthepurpose herein described, with the fixed part K '5 of the rotating clutch, the ring L, the fibrous packing R, and the cylinder-head D, when .the fixed part of the clutch is attached to the,

cylinder-head, substantially as shown, the packing-ring B being formed with acylindrical body flanged at one end for the purpose of being held between the disk K and ring L, the latter being recessed to allow a free admission around the body of the packing-ring of any pressure within the cylinder, the tendency of which is to close the packing-ring around the rotating bar for the purpose of preventing any escape of pressure around the 'LEANDER s; WooDBUnY.

\Vitnesses: .F. G. CoGGIN,

J AS. M. Mna'ron, 

